====== petalinux ======


===== - create project =====


<code bash>
source /xilinx/settings.sh

petalinux-create -t project --template zynq -n xxx_name
petalinux-config --get-hw-description .

</code>


===== - create modules =====
相当于创建linux模块驱动

<code bash>
petalinux-create -t modules -n xxx_module --enable
</code>


===== - create app =====
创建一个linux平台下的app可执行程序

<code bash>
petalinux-create -t apps -n xxx_app  --enable
</code>

然后进入recipes-apps/xxx_app目录，修改files/xxx_app.c文件，默认是一个hello world!打印程序。



===== - build =====
<code bash>
petalinux-build -c rootfs
petalinux-build -c xxx_module
petalinux-build -c xxx_app -x do_install



petalinux-build
</code>

===== - app单独编译&调试 =====

<code bash>
petalinux-build -c xxx_app -x do_compile   # 对指定app进行编译, 编译后生成的app可执行文件在以下位置
ls build/tmp/work/cortexa9hf-neon-xilinx-linux-gnueabi/myapp3/1.0-r0/myapp3

# 然后可以将此文件通过scp的方式，copy到zynq设备，修改权限chmod 777 ./myapp3， 执行程序./myapp3
# 这样的方式不用每次app修改后都烧写到flash， 通过scp的方式加快app开发调试速度。

</code>
===== - package to BOOT.BIN =====

<code bash>
petalinux-package --boot --fsbl zynq_fsbl.elf --u-boot --kernel --fpga system.bit --force
# --boot， 打包成BOOT.BIN文件
# -- 输入fsdb文件
# --u-boot， 输入默认u-boot文件， 一般是指u-boot.elf
# --kernel ，输入petalinux内核， 默认是指image.ub
# --fpga， 指定FPGA bits文件。
#一般是建议先不用--kernel选项生成BOOT.BIN文件，然后将BOOT.BIN文件和image.ub一起copy到SD卡，从SD卡启动看看程序效果，程序稳定后可以再考虑弄成为flash启动，这样调试速度会快一些。
</code>

===== - 一个简单的驱动开发例程——GPIO流水灯（Petalinux部分） =====
https://blog.csdn.net/u013029731/article/details/85042431/




===== - 实现app开机启动 =====

参考ug1144, Ch.7: Customizing the Rootfs

参考： https://blog.csdn.net/qq_37775990/article/details/126951572

<code bash>


实现开机启动
本章节内容参考UG1144。
（1）创建myapp-init应用

cd <plnx-proj-proot>
petalinux-create -t apps --template install -n myapp-init --enable

（2）修改myapp-init.bb配置文件
配置文件的位置在：

project-spec/meta-user/recipes-apps/myapp-init/myapp-init.bb
修改文件内容为：

#
# This file is the myapp-init recipe.
#
SUMMARY = "Simple myapp-init application"
SECTION = "PETALINUX/apps"
LICENSE = "MIT"
LIC_FILES_CHKSUM ="file://${COMMON_LICENSE_DIR}/
MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
SRC_URI = "file://myapp-init \
 "
S = "${WORKDIR}"
FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
inherit update-rc.d
INITSCRIPT_NAME = "myapp-init"
INITSCRIPT_PARAMS = "start 99 S ."
do_install() {
 install -d ${D}${sysconfdir}/init.d
 install -m 0755 ${S}/myapp-init ${D}${sysconfdir}/init.d/myapp-init
}
FILES_${PN} += "${sysconfdir}/*"
（3）修改myapp-init脚本文件内容
脚本文件的位置在：

project-spec/meta-user/recipes-apps/
myapp-init/files/myapp-init

本文修改的内容为加载xilinx-axidma.ko module和在后台启动程序xxx_app

#!/bin/sh

cd /lib/modules/5.4.0-xilinx-v2020.1/extra
insmod xxx_module.ko

cd /usr/bin
./xxx_app &   
## 注意，最好在此加上&，让其后台执行，不然系统会把当前命令执行完之后再进行下面的任务，
##  比如下面的任务是配置网络， 这对于需要网络的开机启动尤其重要

完成后进行petalinux-build，使用新生成的镜像，下次就可以开机自启动了。

</code>


开机启动执行log example:

<code bash>
Hello PetaLinux World, startup test....
blink: loading out-of-tree module taints kernel.
<1>Hello module world.
<1>Module parameters were (0xdeadbeef) and "default"
blink_init: Registers mapped to mmio = 0xf09d0000  
Registeration is a success the major device number is 245.
If you want to talk to the device driver,
create a device file by following command. 
 
mknod /dev/blink_Dev c 245 0

The device file name is important, because
the ioctl program assumes that's the file you'll use
################################ 
      Blink LED Application device_open(c7e4c6c0)
 
################################ 
************************************************ 
start LED sparkle...
************************************************ 
app led on
KERNEL PRINT : set_blink_ctrl 

app led off
KERNEL PRINT : reset_blink_ctrl 

app led on
KERNEL PRINT : set_blink_ctrl 

app led off
KERNEL PRINT : reset_blink_ctrl 

device_release(ef1d9370,c7e4c6c0)
################################ 
INIT: Entering runlevel: 5ation  
Configuring network interfaces... IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
udhcpc (v1.24.1) started
Sending discover...
Sending discover...
macb e000b000.ethernet eth0: link up (1000/Full)
IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
Sending discover...
Sending select for 192.168.0.166...
Lease of 192.168.0.166 obtained, lease time 268435455
/etc/udhcpc.d/50default: Adding DNS 192.168.0.1
done.
Starting Dropbear SSH server: Generating key, this may take a while...
Public key portion is:
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCh7/mYSvw3pyvt0K//+5A2N2sIGUoo7ZXjChqDaBD/iV8MDrVQiGiyyXmxkUlcrgKVeWzP
NQ0Q4i58cvtTIIJmeEQI3rM9WD7V+o/HcDRr8TlyIbK0SOKHCcHpglKwm54e01evpmX2tt4cdXfxdnaRhcONjPMJq4cAutFu0yO85QGwsVQ1
OFJYrdmt4Rc5T0BZdF3LtuXaVOF7mJ7aavI7vpsme1JIvzAOkGMSXH+HqY2wG4Ak6D07WdH78AaQsI86vDLA1WLaPP4oCMjiLjeFKIuAbnhl
d+HuJtwvj5fx4GZcRyQ5VrwVE7anQmAu4Olw/O9dwQQTAJ0LX1u6Ui0V root@petalinux_boot_from_flash
Fingerprint: md5 61:94:fc:ff:b1:94:85:d7:fa:19:26:a9:a4:92:df:7f
dropbear.
hwclock: can't open '/dev/misc/rtc': No such file or directory
Starting syslogd/klogd: done
Starting tcf-agent: OK

PetaLinux 2018.3 petalinux_boot_from_flash /dev/ttyPS0

petalinux_boot_from_flash login: random: crng init done

PetaLinux 2018.3 petalinux_boot_from_flash /dev/ttyPS0

petalinux_boot_from_flash login: 

</code>

从上面的执行log看出来，很明显获取IP地址是在开机启动执行程序完成之后才开始的，所以一定要注意这一点。




===== - zynq设备上运行指定驱动的app程序 =====

在zynq fpga运行过程。

<code>

root@petalinux_boot_from_flash:/lib/modules/4.14.0-xilinx-v2018.3/extra# pwd
/lib/modules/4.14.0-xilinx-v2018.3/extra
root@petalinux_boot_from_flash:/lib/modules/4.14.0-xilinx-v2018.3/extra# ls
blink.ko

modprobe blink.ko     #  加载驱动
mknod /dev/blink_Dev c 245 0   # 标 dev, 这个信息根据modprobe的提示信息输入
ls /dev/blink_Dev    #  已经有dev
blinkapp    # 运用app程序

</code>



===== - linux 加载module =====

<code bash>
insmod blink.ko
# 如果有同名文件module已经加载，可以先lsmode查看

lsmod   # 列出已经加载的module

rmmod blink.ko  # 删除已加载的module, 可以在后面两次加载新的module.


</code>


===== - module驱动代码实例 =====
==== - 一个简单的device module 驱动代码 ====

主要描述用户数据和内核数据之间如何互通，因为不能直接访问，需要通过copy_to_user & copy_from_user函数来完成。

<code c>


#include <linux/uaccess.h>  // copy_to_user copy_from_user

#include <asm/uaccess.h> /* for get_user and put_user */  // raw_copy_to_user, raw_copy_from_user



/*
* This function is called whenever a process which has already opened the
* device file attempts to read from it.
*/
static ssize_t device_read(	struct file *file, /* see include/linux/fs.h */
							char __user * buffer, /* buffer to be filled with data */
							size_t length, /* length of the buffer */
							loff_t * offset)
{
    int ret;

    char k_buffer[20] = {0}; // kernel core buffer

    memcpy(k_buffer, "core_to_user_msg02", length);

    ret = copy_to_user(buffer, k_buffer, length);


	return SUCCESS;
}
/*
* This function is called when somebody tries to
* write into our device file.
*/
static ssize_t device_write(struct file *file,
							const char __user * buffer, 
							size_t length, 
							loff_t * offset)
{

    // user function
    int ret;
    char k_buffer[20] = {0}; // kernel core buffer
    ret = copy_from_user(k_buffer, buffer, length);

    
	  printk("kernel:::  blink write: %s\n", k_buffer);
    // end

	return SUCCESS;
}


</code>



==== - gpio驱动led举例 ====

驱动部分：

<code c>
#include <linux/init.h>     //定义了module_init
#include <linux/module.h>   //最基本的头文件，其中定义了MODULE_LICENSE这一类宏
#include <linux/fs.h>       //file_operations结构体定义在该头文件中
#include <linux/device.h>	//class、device结构体的定义位置
#include <linux/kernel.h>	//printk头文件

#include <linux/uaccess.h>	//copy_from_user头文件
#include <asm/io.h>			//ioremap头文件

#include <linux/ioport.h>
#include <linux/of.h>
#include <linux/delay.h>

//定义主设备号 
static int major_num;
//  定义设备文件名
#define DEVICE_NAME "leds"

//定义class、device结构体
#define CLASS_NAME "mygpio"	
static struct class* gpio_class;    
static struct device* gpio_device; 

#define LEDS_BASE_ADDR		(0x41200000)	//GPIO的Base addr，用于映射
 
static unsigned *leds;

static int leds_drv_open(struct inode *Inode, struct file *File)
{
	*leds = 0x0;				
	return 0;
}
 
 
static ssize_t leds_drv_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
	return 0;
}
 
static ssize_t leds_drv_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
	unsigned int ret = 0;
	unsigned int tmp_val;
	
	ret = copy_from_user(&tmp_val, buf, count);
	
	*leds = tmp_val & 0xf;	
	
	return ret;
}
 
//  描述与设备文件触发的事件对应的回调函数指针
static struct file_operations dev_fops =
{ 
	.owner = THIS_MODULE, 
	.open = leds_drv_open,
	.read = leds_drv_read, 
	.write = leds_drv_write,
};
 
//  初始化Linux驱动
static int __init leds_drv_init(void)
{
	int ret; 
 
	leds = ioremap(LEDS_BASE_ADDR, 0x100);
 
	//获取主设备号
	major_num = register_chrdev(0,DEVICE_NAME, &dev_fops);
	
	//创建设备类
	gpio_class = class_create(THIS_MODULE, CLASS_NAME);    

	if(IS_ERR(gpio_class))
	{                
    	unregister_chrdev(major_num, DEVICE_NAME);
    	printk(KERN_ALERT "Failed to register device class\n");
    	return PTR_ERR(gpio_class);          
    }
    //注册设备
	gpio_device = device_create(gpio_class, NULL, MKDEV(major_num, 0), NULL, DEVICE_NAME);
	
	if(IS_ERR(gpio_device))
	{               
    	class_destroy(gpio_class);           
    	unregister_chrdev(major_num, DEVICE_NAME);
    	printk(KERN_ALERT "Failed to create the device\n");
    	return PTR_ERR(gpio_device);
    }
    printk(KERN_INFO "LED_GPIO_init: device created correctly\n");
 
	return 0;
}
 
// 卸载Linux驱动
static void __exit leds_drv_exit(void)
{
	iounmap(leds);
	
	//  删除设备文件,后创建的先卸载  
	device_destroy(gpio_class, MKDEV(major_num, 0));  
	class_destroy(gpio_class); 

	unregister_chrdev(major_num,DEVICE_NAME);	//释放设备号

	//  输出日志信息
	printk("LED_GPIO_exit success!\n");
} 
 
//  注册初始化Linux驱动的函数
module_init(leds_drv_init);
//  注册卸载Linux驱动的函数
module_exit(leds_drv_exit);

MODULE_LICENSE("GPL");

</code>

应用程序app部分：

<code c>
#include <stdio.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
 
 
 
int main(int argc, char** argv)
{
        int fd;
        
        fd = open("/dev/leds", O_RDWR);
        
        if(fd < 0)
        {
                printf("fd = %d open fialed!\n", fd);
        }

        unsigned int leds = 0;

        while(1)
        {
        	write(fd, &leds, 4);
        
        	leds++;
        	leds %= 0xf;
                sleep(1);
        }

        close(fd);

        return 0;
}


</code>